The KIM method does introduce extra radiation dose to the patient of approximately 65mSv per treatment localised to the prostate 8. Standard treatment doses for prostate radiotherapy are 80 Gy. The amount of imaging dose will be dependent on the imaging field size, frame rate of acquired images, treatment field size, kV energy used and method of treatment delivery (Volumetric Modulated Arc Therapy [VMAT], Intensity Modulated Radiotherapy [IMRT], Stereotactic Boost Radiotherapy [SBRT]).9 We will minimise the imaging dose from our previous study 8 by: